"With some European resolve in regards to the Greece debt situation, oil prices took off late last week," Patrick DeHaan, GasBuddy.com senior petroleum analyst, said in a news release. "While the national average has remained relatively subdued in the last couple weeks, we may see a slow climb in the national average this week.

"As we approach heating oil season, we'll also see support for diesel prices, which is sure to frustrate diesel consumers, who are paying as much as 80 cents more per gallon than gasoline consumers."